Use of separate control channel to mitigate interference problems in wireless networking

Abstract

Described is a system and method for transporting interference-related control data and other information between nodes in a wireless network, using a control channel that is distinct from a content channel used to transport content. The control channel may be a different channel in the same unlicensed band as the content channel, a channel in a different unlicensed band, or a channel in a licensed band, and thereby not subject to the same interference-related problems that the unlicensed content channel may experience. As a result, management information for adjusting the content channel's communication parameters may still be communicated between the nodes, whereby mitigation actions may occur. For example, the content channel may be changed to another frequency, compression may be implemented or varied, and / or the data transfer rate may be varied. The control data can also be used to change the control channel's communication parameters.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]The present invention is related to the following copending United States patent applications filed concurrently herewith, assigned to the assignee of the present invention, and hereby incorporated by reference in their entireties:[0002]“Extensible Framework for Mitigating Interference Problems in Wireless Networking,” U.S. patent application Ser. No. 11 / 004,288; and[0003]“Protocol for Exchanging Control Data to Mitigate Interference Problems in Wireless Networking,” U.S. patent application Ser. No. 11 / 004,428.FIELD OF THE INVENTION[0004]The invention relates generally to radio frequency communications, and more particularly to controlling the communications in environments such as wireless computer networks.BACKGROUND[0005]Wireless local area networks (WLANs) are proliferating in both home and enterprises. Such wireless networks may be used for various types of content transfer, including web browsing, file transferring, audiovisual stre...

AI Technical Summary

Benefits of technology

[0009]Briefly, the present invention is directed towards a system and method for transporting interference-related control data and other information between two or more nodes in a wireless network, using a control channel that is separate from the content (main data) channel used to transport content. The control channel is typically one that is not subject to the same interference-related problems being experienced on the unlicensed content channel, at least with respect to the control data, which requires relatively little bandwidth. As a result, management information (e.g., interference-related data) and the like may still be communicated between nodes, such that the content communication can be dynamically varied in some way to mitigate or avoid the problems being caused by the interference. For example, to avoid or reduce the communication problems caused by interference on the content channel, via management information sent over the control channel, the content channel may be changed to another frequency, and / or compression of the data transfer rate may be varied to correspond to a narrowed amount of bandwidth due to the interference. Even when the content channel is experiencing substantial interference, via the separate control channel the interference information necessary for mitigation is normally able to be shared between wireless nodes.

[0010]Various alternatives for selecting a different control channel are feasible, including selecting the control channel as a different channel in the same unlicensed band as the content channel, selecting the control channel as a channel in a different band (e.g., a channel in the 5 GhZ band instead of in the 2.4 GHz band, or vice-versa), and / or using a channel in a licensed band. The use of a licensed band channel as the control channel for an unlicensed main data channel ensures that control information will not be interfered with by other RF sources (under ordinary circumstances). Note that while licensed band transports can be expensive, the communication of such control information requires relatively low bandwidth, helping lower the cost. For example, a relatively small amount of control data on a licensed band can be used to control large amounts of content data being transported on an unlicensed-band data network (such as an 802.11 WLAN).

[0014]In one implementation, a protocol provides for peer discovery, peer information exchange, and a transport mechanism used to deliver the protocol. According to the protocol, the locally-detected interference-related information is formatted, along with general environment information and the like, into the control data, which is then distributed over the control channel from the local node to a remote peer node in the wireless network that is RCS-enabled (running the robust coexistence service), whereby the remote node knows the local node's current RF environment. A similar exchange of control data occurs in the opposite direction. As a result, the peer nodes know each other's environments, and when any node transmits content (the main data) to a receiver node, the transmission can be adapted to avoid the interference, or mitigate the negative effects of the interference in some way. For example, if an access point knows that a device to which it is associated is experiencing interference on one channel, the access point and device can agree to switch to a different channel. Note that with an access point, each associated computing device has only the access point as its peer, while the access point has a peer relationship with each associated access point. In an ad hoc network, devices may have multiple peers.

[0016]The control data generally contains interference-related information, whether in the form of information about the interference such as the type of interferer, frequency, duty cycle, periodicity of the interference and so forth, and / or an interference mitigation solution. This allows a receiving node to pass information about the receiving RF environment (e.g., its remote interference-related information) to a transmitting node, whereby the node can adapt the transmission in some way to improve the chances of better reception based on the control data. The solution may be to change the content channel, in which event the receiver needs to be informed of the change via management data and agree to it, but may be solely implemented at the transmitting node, such as to lower the data transmission rate. Compression may be selectively employed and / or varied as well, such as when interference is effectively reducing the amount of available bandwidth.

Problems solved by technology

Note that while licensed band transports can be expensive, the communication of such control information requires relatively low bandwidth, helping lower the cost.

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